Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
A key point to remember is that for much of the season, the snowpack has been very shallow. Shallow snow is weak snow, and the faceted layers have remained weak all season long. Typically, by this time of year, we have a deeper snowpack and the facets have had a chance to gain some strength. For now, we have to continue to exercise patience and make careful terrain choices while we wait for this problem to go away. Poor snowpack structure is widespread, and recent stability tests have produced stubborn results. Steep northerly slopes near treeline are the bullseye location for this problem. You are unlikely to see in your face red flag indicators today like collapsing and cracking, but deep, destructive, and deadly human-triggered avalanches remain a real possibility.
The PWL remains active on west-facing slopes, but the avalanche problem is specific to slopes with a relatively deep and layered snowpack. Some west aspects are very thin due to warm temperatures, sun, and wind. These slopes do not pose much of a threat. The only way to know is to probe for depth and dig down to look for weak layers.